China is not only a large exporter of chemical fiber, cotton products, textiles, and clothing, but is also a main producer of textiles. In 2000, the output of the synthetic fiber had reached 10 million tons, which comprises 70% of total amount of fiber in China, much higher than 60% in the worldwide, causing the ratio of natural and chemical fibers to go out of balance. As petroleum, coal and natural gas, which are non-renewable resources, are used as raw materials to produce synthetic fiber, and they will be exhausted in the future, renewable, recyclable, and green environmental friendly resources have attracted increasing attention. Due to reforms and more open policy in China, cotton supply has been in a state of shortage for more than 20 years. The history of silk in China began in the Jiangsu and Zhejiang regions, however, because of the extreme shortage of the land resources and low added value of the textile, the development of the textile has suffered from a lot of restrictions, and thus, during the past decade, the total output has been decreasing year to year. Wool is favored by people, but the annual output and quality of Chinese wool doe not meet domestic demand, so in recent years, a great amount of raw wool, scoured wool, wool top, and wool yarn have been imported every year.
In natural fibers, the development of hemp fiber has the broadest prospects for mass adoption, considering that ramie, flax, jute, and cannabis can be used for textiles, and other hemps (such as sisal, abaca, etc.) fibers can be mostly used for hemp rope, sacks and other industrially packaging materials.
At present, the planting area of flax fiber crops in China is about 3 million mus (1 mus=6000/9 m2) which has surpassed that of France, Britain, and Russia, however, the average output and fiber percentages in China are low, which is about 50% lower than in developed countries. Because the technology for processing flax in China is antiquated, the fiber percentage (long hemp) is only 11%-13%, and strength is not high, moreover the end breakage rate is high, therefore, it is difficult to produce spun yarn. Thus, it is urgent to develop a new process and a new technology to solve the above problems.
Generally, the perennial ramie planting area in China is 1.50-3.00 million mus and the output of fiber is about 0.25 million tons which accounts for more than 90% of global output. However, the present production technology and production equipment, which are the technological the equivalent 1950s and 1960s industry, is antiquated, characterized by low productivity, a harsh production environment, and serious environment contamination, due to the large volume of sewage produced in the process, which seriously influences the development of ramie processing.
Cannabis, which has a fiber output per mu higher than ramie and flax, is a kind of traditionally planted hemp crops in China, and cannabis fiber has excellent moisture absorption and permeation, natural antimicrobial activity, pliability and comfort, anti-ultraviolet properties, sound absorption, odor adsorption, and other functions. Cannabis textile has a unique style, and therefore, it is very popular in European and American clothing markets. Nevertheless, the current main bottleneck and restricting factors in cannabis fiber processing are as follows: (1) Cannabis planting: the different uses of cannabis fiber have different requirements for planting and harvesting; (2) Cannabis bast fiber producing: namely, the separation of cannabis skin from cannabis stem. The separation of skin from stem in Chinese traditional processing belongs to a labor intensive processing, that is to say, hand stripping process, which greatly limits processing efficiency and increases labor costs; (3) Cannabis bast fiber degumming: compared with flax and ramie, cannabis has higher contents of lignin, hemi-cellulose, pectin and other non-cellulose ingredients, and the distribution and ease of degumming of each ingredient in the cannabis bast are different from other hemp basts. Further, the individual fiber length of cannabis is shorter, thus, it is difficult to control the degumming level, which is a technical problem that has not been solved for many years in the world; (4) The traditional process for processing cannabis fiber is time consuming, characterized by old production equipments, little mechanization and automation, intensive, low productivity labor, old processing technology, large energy consumption, the production of a large amount of sewage which cause serious environmental problem, and low fiber availability and quality which make it difficult to produce a high grade product. All of these are the problems that need to be solved urgently.